|Publication number||US7483197 B2|
|Application number||US 11/390,996|
|Publication date||27 Jan 2009|
|Filing date||28 Mar 2006|
|Priority date||5 Oct 1999|
|Also published as||US7110158, US7187489, US7236284, US7355782, US7388706, US7830586, US7839559, US8264763, US8416487, US8643935, US20030043157, US20050286113, US20060033975, US20060250337, US20060262126, US20060284877, US20070146376, US20080191978, US20090122036, US20090219604, US20110037907, US20120182595, WO2003007049A1|
|Publication number||11390996, 390996, US 7483197 B2, US 7483197B2, US-B2-7483197, US7483197 B2, US7483197B2|
|Inventors||Mark W. Miles|
|Original Assignee||Idc, Llc|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (100), Non-Patent Citations (88), Referenced by (32), Classifications (70), Legal Events (3)|
|External Links: USPTO, USPTO Assignment, Espacenet|
This application is a continuation of U.S. application Ser. No. 09/413,222 filed on Oct. 5, 1999, now U.S. Pat. No. 7,123,216 which is hereby incorporated by reference in its entirety.
This application also hereby incorporates by reference the entire disclosure of each of U.S. application Ser. No. 08/744,253, filed Nov. 5, 1996, now U.S. Pat. No. 5,986,796, PCT Application No. PCT/US95/05358, filed May 1, 1995, and U.S. application Ser. No. 08/238,750, filed May 5, 1994, now U.S. Pat. No. 5,835,255.
This invention relates to interferometric modulation.
2. Description of the Related Technology
Interferometric modulators (IMods) modulate incident light by the manipulation of the optical properties of a micromechanical device. This is accomplished by altering the device's interferometric characteristics using a variety of techniques. IMods lend themselves to a number of applications ranging from flat panels displays and optical computing to fiber-optic modulators and projection displays. The different applications can be addressed using different IMod designs.
In general, in one aspect, the invention features an IMod based display that incorporates anti-reflection coatings and/or micro-fabricated supplemental lighting sources.
In general, in one aspect, the invention features an efficient drive scheme for matrix addressed arrays of IMods or other micromechanical devices.
In general, in one aspect, the invention features a color scheme that provides a greater flexibility.
In general, in one aspect, the invention features electronic hardware that can be field reconfigured to accommodate different display formats and/or application functions.
In general, in one aspect, the invention features an IMod design that decouples the IMod's electromechanical behavior from the IMod's optical behavior.
In general, in one aspect, the invention features an IMod design with alternative actuation means, some one of which may be hidden from view.
In general, in one aspect, the invention features an IMod or IMod array that is fabricated and used in conjunction with a MEMS switch or switch array, and/or MEMS based logic.
In general, in one aspect, the invention features an IMod that can be used for optical switching and modulation.
In general, in one aspect, the invention features IMods that incorporate 2-D and 3-D photonic structures.
In general, in one aspect, the invention features a variety of applications for the modulation of light.
In general, in one aspect, the invention features a MEMS manufacturing and packaging approach based on a continuous web fed process.
In general, in one aspect, the invention features IMods used as test structures for the evaluation of residual stress in deposited films.
An attribute of one previously described IMod design (the induced absorber design described in U.S. patent application Ser. No. 08/554,630, filed on Nov. 6, 1995, and incorporated by reference) is the efficiency of its dark state, in which it can absorb as much as 99.7% of light which is incident upon it. This is useful in reflective displays. In the described design, the IMod reflects light of a certain color in the un-actuated state, and absorbs light in the actuated state.
Because the IMod array resides on a substrate, the potential for absorption is diminished by the inherent reflection of the substrate. In the case of a glass substrate, the amount of reflection is generally about 4% across the visible spectrum. Thus, despite the absorptive capability of the IMod structure, a dark state can only be as dark as the front surface reflection from the substrate will permit.
One way to improve the overall performance of an IMod based display is by the incorporation of anti-reflection coatings (AR coatings). These coatings can comprise one or more layers of dielectric films deposited on the surface of a substrate and are designed to reduce the reflection from that surface. There are many different possible configurations for such films and design and fabrication is a well known art. One simple film design is a single coating of magnesium fluoride approximately one-quarter wave thick. Another example utilizes a quarter wave film of lead fluoride deposited on the glass, followed by a quarter wave film of magnesium fluoride, with yet a third example interposing a film of zinc sulfide between the two.
Techniques used in the manufacture of micro mechanical structures may be applied to the fabrication of microscopic discharge or arc lamps. Because of the microscopic size of these “micro-lamps”, the voltages and currents to drive them are significantly lower than those required to supply arc lamps fabricated using conventional means and sizes. In the example of
Next, electrode layer 206 is deposited and patterned to form two separate electrodes. This material could be a refractory metal like tungsten and would have a thickness that is sufficient to provide mechanical support, on the order of several thousand angstroms. Then sacrificial layer 202 is removed using a dry release technique. The assembly (in the form of an array of such lamps) is sealed by bonding to a glass plate like substrate 106 (shown in
The application of sufficient voltage to the electrodes of each lamp will result in an electrical discharge, in the gas between the ends of the electrodes, and the emission of light 205 in a direction away from the reflector 204. This voltage could be as low as several tens of volts if the gap spacing is on the order of several hundred microns or less. If the electrode material is deposited with minimal stress, the sacrificial layer, 202, will determine the position of the electrodes within the bowl. In this case, the thickness is chosen to position the discharge at the focal point of the bowl. Should there be residual stress, which would cause the electrodes to move when released, then thickness is chosen to compensate for this movement. In general the thickness will be some fraction of the depth of the bowl, from several to tens of microns.
Referring again to
The lamps may be fabricated without including the reflector layer so that they may emit light omnidirectionally.
Lamps fabricated with or without the reflector may be used in a variety of applications requiring microscopic light sources or light source arrays. These could include projection displays, backlights for emissive flat panel displays, or ordinary light sources for internal (homes, buildings) or external (automobiles, flashlights) use.
When light trapped within the guide is incident upon the scatter pad, the conditions for total internal reflection are violated and some portion 129 of the light scatters in all directions. Scattered light which would normally escape into the surrounding medium, i.e. towards the viewer, 128, is reflected into substrate 112 due to the presence of the reflective side of coating 126. Like the aforementioned micro-lamps, the scatter pads are fabricated in an array, with each pad dimensioned such that the portion of the display that it obscures from direct view is hardly noticeable. While these dimensions are small, on the order of tens of microns, they can provide sufficient supplemental lighting because of the inherent optical efficiency of the underlying IMod array 114. The shape of the scatter pad may be circular, rectangular, or of arbitrary shapes which may minimize their perception by the viewer.
Addressing Elements in an Array
In order to actuate arrays of IMods in a coordinated fashion for display purposes, a sequence of voltages is applied to the rows and columns of the array in what is generally known as a “line at a time” fashion. The basic concept is to apply a sufficient voltage to a particular row such that voltages applied to selected columns cause corresponding elements on the selected row to actuate or release depending on the column voltage. The thresholds and applied voltages must be such that only the elements on the selected row are affected by the application of the column voltages. An entire array can be addressed over a period of time by sequentially selecting the set of rows comprising the display.
One simple way of accomplishing this is shown in
The addressing occurs in alternating frames 0 and 1. In a typical addressing sequence, data for row 0 is loaded into the column drivers during frame 0 resulting in either a voltage level of Vcol1 or Vcol0 being applied depending on whether the data is a binary one or zero respectively. When the data has settled, row driver 0 applies a select pulse with the value of Vsel F0. This results in any IMods on columns with Vcol0 present becoming actuated, and IMods on columns with Vcol1 present, releasing. The data for the next row is loaded into the columns and a select pulse applied to that row and so on sequentially until the end of the display is reached. Addressing is then begun again with row 0; however this time the addressing occurs within frame 1.
The difference between the frames is that the correspondence between data and column voltages is switched, a binary zero is now represented by Vcol0, and the row select pulse is now at the level of Vsel F1. Using this technique, the overall polarity of the voltages applied to the display array is alternated with each frame. This is useful, especially for MEMS based displays, because it allows for the compensation of any DC level charge buildup that can occur when only voltages of a single polarity are applied. The buildup of a charge within the structure can significantly offset the electroptical curve of the IMod or other MEM device.
Color Display Scheme
Because the IMod is a versatile device with a variety of potential optical responses, a number of different color display schemes are enabled having different attributes. One potential scheme exploits the fact that there are binary IMod designs that are capable of achieving color states, black states, and white states in the same IMod. This capability can be used to achieve a color scheme that can be described as “base+pigment”. This terminology is used because the approach is analogous to the way in which paint colors are produced by adding pigments to a white base to achieve a desired color. Using this approach, a particular paint can attain any color in the spectrum and any level of saturation by controlling the content and amount of pigments that are added to the base. The same can be said for a display that incorporates colored and black and white pixels.
As shown in
User Control of Color Scheme
The previously described color scheme, as well as the inherent attributes of an IMod-based display in terms of resolution, gray scale depth, and refresh rate, provides flexibility in display performance. Given this range, it is useful to give the user of a product containing such a display control over its general characteristics. Alternatively, it may be advantageous for the display to automatically adapt to different viewing needs.
For example, a user may want to use a product in black and white mode if, some context, only text were being viewed. In another situation, however, the user may want to view high quality color still images, or in yet another mode may want to view live video. Each of these modes, while potentially within the range of a given IMod display configuration, requires tradeoffs in particular attributes. Tradeoffs include the need for low refresh rates if high-resolution imagery is required, or the ability to achieve high gray scale depth if only black and white is requested.
To give the user this kind of on demand flexibility, the controller hardware may be reconfigurable to some extent. Tradeoffs are a consequence of the fact that any display has only a certain amount of bandwidth, which is fundamentally limited by the response time of the pixel elements and thus determines the amount of information which can be displayed at a given time.
One display architecture that could provide such flexibility is illustrated in
The controller 412 provides signals and data to the driver electronics 414 and 416 for addressing the display 418. Conventional controllers are based on IC's or Application Specific Integrated Circuits (ASICs), which are effectively “programmed” by virtue of their design during manufacture. The term program, in this case, means an internal chip layout comprising numerous basic and higher level logical components (logic gates and logic modules or assemblies of gates). By using field programmable devices such PLAs or FPGAs, different display configurations may be loaded into the display controller component in the form of hardware applications or “hardapps”, from a component 410, which could be memory or a conventional microprocessor and memory. The memory could be in the form of EEPROMS or other reprogrammable storage devices, and the microprocessor could take on the form of simple microcontroller whose function is to load the hardapp from memory into the FPGA, unless this were performed by whatever processor is associated with the general functioning of the product. This approach is advantageous because with relatively simple circuitry it is possible to achieve a wide variety of different display performance configurations and mixed display scan rates, along with the potential to combine them.
One portion of the screen, for example, might be operated as a low-resolution text entry area, while another provides high quality rendition of an incoming email. This could be accomplished, within the overall bandwidth limitations of the display, by varying the refresh rate and # of scans for different segments of the display. The low-resolution text area could be scanned rapidly and only once or twice corresponding to one or two bits of gray scale depth. The high rendition email area could be scanned rapidly and with three or four passes corresponding to three or four bits of grayscale.
Configurable Electronic Products
This idea may be generalized to include not just the functionality of the display controller, but also the functionality of the overall product.
In personal computers, power consumption is not an issue, and the user typically wants to run a large number of complicated software applications. The opposite is true of typical display centric/personal electronic products. They are required to consume low power and offer a relatively small number of relatively simple programs. Such a regime favors implementing the special purpose programs, which could include web browsers, calendar functions, drawing programs, telephone/address databases, and handwriting/speech recognition among others, as hardapps. Thus whenever a particular mode of functionality, e.g., a program, is required by the user, the core processor is reconfigured with the appropriate hardapp and the user interacts with the product. Thus the hardapp processor, a variant of a Field Programmable Gate Array has the hardapp (i.e. program) manifested in its internal logic and connections, which get re-arranged and re-wired every time a new hardapp is loaded. Numerous suppliers of these components also provide an application development system that allows a specialized programming language (a hardware description language) to be reduced into the logical representation that makes up the appropriate processor. Numerous efforts are also underway to simplify the process or reducing higher level programming languages into this form as well. One approach to realizing such a processor is detailed in the paper Kouichi Nagami, et al, “Plastic Cell Architecture: Towards Reconfigurable Computing for General-Purpose”, Proc. IEEE Workshop on FPGA-based Custom Computing Machines, 1998.
Referring again to
Decoupling Electromechanical Aspects from Optical Aspects
U.S. patent application Ser. No. 08/769,947, filed on Dec. 19, 1996, and Ser. No. 09/056,975 filed on Apr. 4, 1998, and incorporated by reference, have described IMod designs that propose to decouple the electromechanical performance of an IMod from its optical performance. Another way in which this may be accomplished is illustrated in
An optical cavity 505 is formed between membrane/mirror 506 and secondary mirror 508. Support for secondary mirror 508 is provided by a transparent superstructure 510, which can be a thick deposited organic, such as SU-8, polyimide, or an inorganic material. With no voltage applied, the membrane/mirror 506, maintains a certain position shown in
In another example, shown in
The device's functionality may be improved by making it interferometric. The IMod variation is shown in
Application of a voltage between aluminum membrane 702 and stack 704 causes the membrane 702 to lie flat against the stack. During fabrication, aluminum 702, which could also include other reflective metals (silver, copper, nickel), or dielectrics or organic materials which have been undercoated with a reflective metal, is deposited on a thin sacrificial layer so that it may be released, using wet etch or gas phase release techniques. Aluminum membrane 702 is further mechanically secured to the substrate by a support tab 716, which is deposited directly on optical stack 704. Because of this, light that is incident on the area where the tab and the stack overlap is absorbed making this mechanically inactive area optically inactive as well. This technique eliminates the need for a separate black mask in this and other IMod designs.
Incident light 706 is either completely absorbed or a particular frequency of light 708, is reflected depending on the spacing of the layers of the stack. The optical behavior is like that of the induced absorber IMod described in U.S. patent application Ser. No. 08/688,710, filed on Jul. 31, 1996, and incorporated by reference.
As shown in
In a transmissive mode of operation, the shutter would either block incident light or allow it to pass through.
Operation of the device may be further enhanced by the addition of supplementary electrode 814, which provides additional torque to the shutter when charged to a potential that induces electrostatic attraction between supplementary electrode 814 and shutter 812. Supplementary electrode 814 comprises a combination of a conductor 814 and support structure 816. The electrode may comprise a transparent conductor such as ITO that could be about thousand angstroms thick. All of the structures and associated electrodes are machined from materials that are deposited on the surface of a single substrate, i.e. monolithically, and therefore are easily fabricated and reliably actuated due to good control over electrode gap spaces. For example, if such an electrode were mounted on an opposing substrate, variations in the surface of both the device substrate and opposing substrate could combine to produce deviations as much as several microns or more. Thus the voltage required to affect a particular change in behavior could vary by as much as several tens of volts or more. Structures that are monolithic follow substrate surface variations exactly and suffer little such variation.
For IMods that are binary devices only a small number of voltage levels is required to address a display. The driver electronics need not generate analog signals that would be required to achieve gray scale operation.
Thus, the electronics may be implemented using other means as suggested in U.S. patent application Ser. No. 08/769,947, filed on Dec. 19, 1996 and incorporated by reference. In particular the drive electronics and logic functions can be implemented using switch elements based on MEMS.
Fabrication of the switch elements as MEMS devices makes it possible to fabricate an entire display system using a single process. The switch fabrication process becomes a subprocess of the IMod fabrication process and is illustrated in
Multidimensional Photonic Structures
In general, IMods feature elements that have useful optical properties and are movable by actuation means with respect to themselves or other electrical, mechanical or optical elements.
Assemblies of thin films to produce interferometric stacks are a subset of a larger class of structures that we shall refer to as multidimensional photonic structures. Broadly, we define a photonic structure as one that has the ability to modify the propagation of electromagnetic waves due to the geometry and associated changes in the refractive index of the structure. Such structures have a dimensional aspect because they interact with light primarily along one or more axes. Structures that are multidimensional have also been referred to as photonic bandgap structures (PBG's) or photonic crystals. The text “Photonic Crystals” by John D. Joannopoulos, et al describes photonic structures that are periodic.
A one-dimensional PBG can occur in the form of a thin film stack. By way of example,
Fabricated on a substrate 1100 (glass is one possibility though there are many others), the structure is essentially a circular waveguide whose refractive index and dimensions w, r, and h determine the frequencies and modes of light which will propagate within it. Such a resonator, if designed correctly, can act as a frequency selective filter for broadband radiation that is coupled into it. In this case, the radiation is generally propagating in the XY plane as indicated by orientation symbol 1101. The one-dimensional analog of this device would be a Fabry-Perot filter made using single layer mirrors. Neither device exhibits a high order optical periodicity, due to the single layer “boundaries” (i.e. mirrors); however, they can be considered photonic structures in the broad sense.
A more traditional PBG is shown in
Because of its periodic nature, the array of
The relevant dimensions of the structure of
Photonic structures also make it possible to direct radiation under restrictive geometric constraints. Thus they are quite useful in applications where it is desirable to redirect and/or select certain frequencies or bands of frequencies of light when dimensional constraints are very tight. Waveguides, channeling light propagating in the XY plane, may be fabricated which can force light to make 90 degree turns in a space less than the wavelength of the light. This can be accomplished, for example, by creating the column defect in the form of a linear row, which can act as the waveguide.
A three-dimensional structure is illustrated in
Three-dimensional PBGs are more complicated to make. Conventional means for fabricating one-dimensional or two-dimensional features, if applied in three dimensions, would involve multiple applications of deposition, pattern, and etch cycles to achieve the third dimension in the structure. Fabrication techniques for building periodic three-dimensional structures include: holographic, where a photosensitive material is exposed to a standing wave and replicates the wave in the form of index variations in the material itself; self-organizing organic or self-assembling materials that rely on innate adhesion and orientation properties of certain co-polymeric materials to create arrays of columnar or spherical structures during the deposition of the material; ceramic approaches that can involve the incorporation of a supply of spherical structures of controlled dimensions into a liquid suspension that, once solidified, organizes the structures, and can be removed by dissolution or high temperature; combinations of these approaches; and others.
Co-polymeric self-assembly techniques are especially interesting because they are both low temperature and require minimal or no photolithography. In general, this technique involves the dissolution of a polymer, polyphenylquinoine-block-polystyrene (PPQmPSn) is one example, into a solvent such as carbon disulfide. After spreading the solution onto a substrate and allowing the solvent to evaporate, a close packed hexagonal arrangement of air filled polymeric spheres results. The process can be repeated multiple times to produce multi-layers, the period of the array may be controlled by manipulating the number of repeat units of the components (m and n) of the polymer. Introduction of a nanometer sized colloid comprising metals, oxides, or semiconductors that can have the effect of reducing the period of the array further, as well as increasing the refractive index of the polymer.
Defects may be introduced via direct manipulation of the material on a submicron scale using such tools as focused ion beams or atomic force microscopes. The former may be used to remove or add material in very small selected areas or to alter the optical properties of the material. Material removal occurs when the energetic particle beam, such as that used by a Focused Ion Beam tool, sputters away material in its path. Material addition occurs when the focused ion beam is passed through a volatile metal containing gas such as tungsten hexafluoride (for tungsten conductor) or silicon tetrafluoride (for insulating silicon dioxide). The gas breaks down, and the constituents are deposited where the beam contacts the substrate. Atomic force microscopy may be used to move materials around on the molecular scale.
Another approach involves the use of a technique that can be called micro-electrodeposition and which is described in detail in U.S. Pat. No. 5,641,391. In this approach a single microscopic electrode can be used to define three-dimensional features of submicron resolution using a variety of materials and substrates. Metal “defects” deposited in this way could be subsequently oxidized to form an dielectric defect around which the PBG array could be fabricated using the techniques described above.
The existence of surface features, in the form of patterns of other materials, on the substrate upon which the PBG is fabricated may also serve as a template for the generation of defects within the PBG during its formation. This is particularly relevant to PBG processes that are sensitive to substrate conditions, primarily self-assembly approaches. These features may encourage or inhibit the “growth” of the PBG in a highly localized region around the seed depending on the specific nature of the process. In this way, a pattern of defect “seeds” may be produced and the PBG formed afterwards with the defects created within during the PBG formation process.
Thus, the class of devices known as IMods may be further broadened by incorporating the larger family of multidimensional photonic structures into the modulator itself. Any kind of photonic structure, which is inherently a static device, may now be made dynamic by altering its geometry and/or altering its proximity to other structures. Similarly, the micromechanical Fabry-Perot filter (shown in
Driving the IMod to force the microring into intimate contact with the substrate and waveguides alters the optical behavior of the device. Light propagating in waveguide 1302 may now couple into the microring by the phenomenon of evanescence. The microring, if sized appropriately, acts as an optical resonator coupling a selected frequency from waveguide 1302 and injecting it into waveguide 1301. This is shown in
Another example is illustrated in
On the inner surface of the membrane 1315 are fabricated two isolated columns 1311, which are directed downwards, and have the same dimensions and are of the same material (or optically equivalent) as the columns on the substrate. The resonator and columns are designed to complement each other; there is a corresponding absence of a column in the resonator where the column on the membrane is positioned.
When the IMod is in an undriven state, there is a finite vertical airgap 1312, of at least several hundred nanometers between the PBG and the membrane columns and therefore no optical interaction occurs. The absence of columns in the resonator act like defects, causing coupling between waveguides 1330 and 1332. In this state the device acts as does the one shown in
Driving the IMod into contact with the PBG, however, places the columns into the resonator altering its behavior. The defects of the resonator are eliminated by the placement of the membrane columns. The device in this state acts as does the one shown in
A static version of this geometry is described in the paper H. A. Haus “Channel drop filters in photonic crystals”, Optics Express, vol. 3, no. 1, 1998.
The materials are configured so that in the undriven state the device reflects in a particular wavelength region, but becomes very absorbing when the membrane is driven into contact. Side view 1410 shows a view of the device looking into the side of the substrate. Light beam 1408 propagates at some arbitrary angle through the substrate and is incident on IMod 1406, shown in the un-driven state. Assuming the frequency of the light corresponds with the reflective region of the IMod in the un-driven state, the light is reflected at a complementary angle and propagates away. Side view, 1414, shows the same IMod in the driven state. Because the device is now very absorbing, the light which is incident upon it is no longer reflected but absorbed by the materials in the IMod's stack.
Thus, in this configuration, the IMod may act as an optical switch for light that is propagating within the substrate upon which it is fabricated. The substrate is machined to form surfaces that are highly polished, highly parallel (to within 1/10 of a wavelength of the light of interest), and many times thicker (at least hundreds of microns) than the wavelength of light. This allows the substrate to act as a substrate/waveguide in that light beams propagate in a direction which is, on average, parallel to the substrate but undergo multiple reflections from one surface to another. Light waves in such a structure are often referred to as substrate guided waves.
To incident light, the IMod operates as an absorbing region whose area depends on the value of the applied voltage. Side view 1434 shows the effect on a substrate propagating beam when no voltage is applied. The corresponding reflective area 1429, which shows the IMod from the perspective of the incident beam, shows “footprint” 1431 of the beam superimposed on the reflective area. Since the entire area 1429 is non-absorbing, beam, 1430, is reflected from IMod 1428 (with minimal losses) in the form of beam 1432.
In side view 1436, an interim voltage value is applied and the reflected beam 1440 has been attenuated to some extent because the reflective area, shown in 1437 is now partially absorbing. Views 1438 and 1429 reveal the result of full actuation and the complete attenuation of the beam.
Thus, by using a tapered geometry a variable optical attenuator may be created, the response of which is directly related to the value of the applied voltage.
Another kind of optical switch is illustrated in
The standoff is fabricated from a material that has the same or higher index of refraction than that of the substrate. This could be SiO2 (same index) or a polymer whose index can be varied. The standoff is machined so that the mirror is supported at an angle of 45 degrees. Machining of the standoff can be accomplished using a technique known as analog lithography that relies on a photomask whose features are continuously variable in terms of their optical density. By appropriate variation of this density on a particular feature, three-dimensional shapes can be formed in photoresist that is exposed using this mask. The shape can then be transferred into other materials via reactive ion etching. The entire assembly is suspended over conductor, 1503, which has been patterned to provide an unobstructed “window” 1505 into the underlying substrate, 1504. That is to say the bulk of conductor 1503 has been etched away so that window 1505, comprising bare glass, is exposed. The switch, like other IMods, can be actuated to drive the whole assembly into contact with the substrate/waveguide. Side view, 1512, shows the optical behavior. Beam 1510 is propagating within the substrate at an angle 45 degrees from normal that prevents it from propagating beyond the boundaries of the substrate. This is because 45 degrees is above the angle known as the critical angle, which allows the beam to be reflected with minimal or no losses at the interface 1519 between the substrate and the outside medium by the principle of total internal reflection (TIR).
The principle of TIR depends on Snell's law, but a basic requirement is that the medium outside the substrate have an index of refraction that is lower than that of the substrate. In side view, 1512, the device is shown with the switch 1506 in the un-driven state, and beam 1510 propagating in an unimpeded fashion. When switch 1506 is actuated into contact with the substrate as shown in side view 1514, the beam's path is altered. Because the standoff has a refractive index greater than or equal to that of the substrate, the beam no longer undergoes TIR at the interface. The beam propagates out of the substrate into the optical standoff, where it is reflected by the mirror. The mirror is angled, at 45 degrees, such that the reflected beam is now traveling at an angle which is normal to the plane of the substrate. The result is that the light may propagate through the substrate interface because it no longer meets the criteria for TIR, and can be captured by a fiber coupler 1520, which has been mounted on the opposite side of the substrate/waveguide. A similar concept is described in the paper, X. Zhou, et al, “Waveguide Panel Display Using Electromechanical Spatial Modulators”, SID Digest, vol. XXIX, 1998. This particular device was designed for emissive display applications. The mirror may also be implemented in the form of a reflecting grating, which may be etched into the surface of the standoff using conventional patterning techniques. This approach, however, exhibits wavelength dependence and losses due to multiple diffraction orders that are not an issue with thin film mirrors. Additionally, alternative optical structures may be substituted for the mirror as well with their respective attributes and shortcomings. These can be categorized as refractive, reflective, and diffractive and can include micro-lenses (both transmissive and reflective), concave or convex mirrors, diffractive optical elements, holographic optical elements, prisms, and any other form of optical element which can be created using micro-fabrication techniques. In the case where an alternative optical element is used, the standoff and the angle it imparts to the optic may not be necessary depending on the nature of the micro-optic.
This variation on the IMod acts as a de-coupling switch for light. Broadband radiation, or specific frequencies if the mirror is designed correctly, can be coupled out of the substrate/waveguide at will. Side view 1526 shows a more elaborate implementation in which an additional fixed mirror, angled at 45 degrees, has been fabricated on the side of the substrate opposite that of the de-coupling switch. This mirror differs from the switch in that it cannot be actuated. By careful selection of the angles of the mirrors on both structures, light 1522 that has been effectively decoupled out of the substrate by switch 1506 may be re-coupled back into the substrate by re-coupling mirror 1528. However, by fabricating the re-coupling mirror with different orientations in the XY plane, the mirror combination may be used to redirect light in any new direction within the substrate/waveguide. The combination of these two structures will be referred to as a directional switch. Re-coupling mirrors can also be used to couple any light that is propagating into the substrate in a direction normal to the surface.
Beam 1702 is incident upon Fabry-Perot 1704, which transmits a particular frequency of light 1708 while reflecting the rest 1709. The transmitted frequency is incident onto and reflected from the reflective superstructure 1706, and is reflected again by mirror 1716 onto angled mirror 1710. Mirror 1710 is tilted such that the light is directed towards antireflection coating 1712 at a normal angle with respect to the substrate, and passes through and into the external medium. The device as a whole thus acts as a wavelength selective filter.
The superstructure may be fabricated using a number of techniques. One would include the bulk micromachining of a slab of silicon to form a cavity of precise depth, e.g., on the order of the thickness of the substrate and at least several hundred microns. The angled mirror is fabricated after cavity etch, and the entire assembly is bonded to the substrate, glass for example, using any one of many silicon/glass bonding techniques.
Optical Mixer Using Substrate Waveguide
This structure produces the same result as a recoupling mirror, except that the mirror is parallel to the surface of the substrate. Because the mirror is suspended a fixed distance beyond the substrate surface, the position of the point of incidence on the opposite substrate interface is shifted towards the right. This shift is directly determined by the height of the repositioner. The beam 1819, containing the unselected wavelengths, is also shifted by virtue of repositioner 1818. The result is that all three beams are equally separated when they are incident on an array of decoupling switches 1820 and 1824. These serve selectively to redirect the beams into one of two optical combiners, 1828 being one of them or into detector/absorber 1830. The optical combiners may be fabricated using a variety of techniques. A polymeric film patterned into the form of a pillar with its top formed into a lens using reactive ion etching is one approach. The absorber/detector, comprising a semiconductor device that has been bonded to the substrate, serves to allow the measurement of the output power of the mixer. Optical superstructures 1829 support external optical components and provide a hermetic package for the mixer.
The combination of planar IMods and a substrate waveguide provide a family of optical devices that are easily fabricated, configured, and coupled to the outside world because the devices reside on the waveguide and/or on the superstructure and are capable of operating on light which is propagating within the waveguide, and between the waveguide and the superstructure. Because all of the components are fabricated in a planar fashion, economies of scale can be achieved by bulk fabrication over large areas, and the different pieces maybe aligned and bonded easily and precisely. In addition, because all of the active components exhibit actuation in a direction normal to the substrate, they are relatively simple to fabricate and drive, compared to more elaborate non-planar mirrors and beams. Active electronic components may be bonded to either the superstructure or the substrate/waveguide to increase functionality. Alternatively, active devices may be fabricated as a part of the superstructure, particularly if it is a semiconductor such as silicon or gallium arsenide.
Printing Style Fabrication Processes
Because they are planar and because many of the layers do not require semiconducting electrical characteristics that require specialized substrates, IMods, as well as many other MEM structures, may take advantage of manufacturing techniques which are akin to those of the printing industry. These kinds of processes typically involve a “substrate” which is flexible and in the form of a continuous sheet of say paper or plastic. Referred to as web fed processes, they usually involve a continuous roll of the substrate material which is fed into a series of tools, each of which selectively coats the substrate with ink in order to sequentially build up a full color graphical image. Such processes are of interest due to the high speeds with which product can be produced.
The metal master is mounted on a drum that is pressed against the sheet with enough pressure to deform the plastic to form the depressions. View 1906 illustrates this. Coater 1908 deposits thin layers of material using well known thin film deposition processes, such as sputtering or evaporation. The result is a stack 1910 of four films comprising an oxide, a metal, an oxide, and a sacrificial film. These materials correspond to the induced absorber IMod design. A tool 1912 dispenses, cures, and exposes photoresist for patterning these layers. Once the pattern has been defined, the film etching occurs in tool 1914. Alternatively, patterning may be accomplished using a process known as laser ablation. In this case, a laser is scanned over the material in a manner that allows it to be synchronized with the moving substrate. The frequency and power of the laser is such that it can evaporate the materials of interest to feature sizes that are on the order of microns. The frequency of the laser is tuned so that it only interacts with the materials on the substrate and not the substrate itself. Because the evaporation occurs so quickly, the substrate is heated only minimally.
In this device example, all of the films are etched using the same pattern. This is seen in 1918 where the photoresist has been stripped away after the application of tool 1916. Tool 1920, is another deposition tool that deposits what will become the structural layer of the IMod. Aluminum is one candidate for this layer 1922. This material may also include organic materials which exhibit minimal residual stress and which may be deposited using a variety of PVD and PECVD techniques. This layer is subsequently patterned, etched, and stripped of photoresist using tools 1924, 1926, and 1928 respectively. Tool 1930 is used to etch away the sacrificial layer. If the layer is silicon, this can be accomplished using XeF2, a gas phase etchant used for such purposes. The result is the self-supporting membrane structure 1932 that forms the IMod.
Packaging of the resulting devices is accomplished by bonding flexible sheet 1933 to the top surface of the substrate sheet. This is also supplied by a continuous roll 1936 that has been coated with a hermetic film, such as a metal, using coating tool 1934. The two sheets are joined using bonding tool 1937, to produce the resulting packaged device 1940.
Residual stress is a factor in the design and fabrication of MEM structures. In IMods, and other structures in which structural members have been mechanically released during the fabrication process, the residual stress determines the resulting geometry of the member.
The IMod, as an interferometric device, is sensitive to variations in the resulting geometry of the movable membrane. The reflected, or in other design cases transmitted, color is a direct function of the airgap spacing of the cavity. Consequently, variations in this distance along the length of a cavity can result in unacceptable variations in color. On the other hand, this property is a useful tool in determining the residual stress of the structure itself, because the variations in the color can be used to determine the variations and degree of deformation in the membrane. Knowing the deformed state of any material allows for a determination of the residual stresses in the material. Computer modeling programs and algorithms can use two-dimensional data on the deformation state to determine this. Thus the IMod structure can provide a tool for making this assessment.
The imaging device is connected to a computer system 2036, upon which resides hardware and capable of recording and processing the image data. The hardware could comprise readily available high speed processing boards to perform numerical calculations at high rates of speed. The software may consist of collection routines to collect color information and calculate surface deformations. The core routine would use the deformation data to determine the optimal combination of uniform stress and stress gradient across the thickness of the membrane, which is capable of producing the overall shape.
One mode of use could be to generate a collection of “virgin” test wafers with detailed records of their non-deposited stress states, to be put away for later use. When the need arises to determine the residual stress of a deposited film, a test wafer is selected and the film is deposited on top of it. The deposited film alters the geometry of the structures and consequently their color maps. Using software resident on the computer system, the color maps of the test wafer both before and after may be compared and an accurate assessment of the residual stress in the deposited film made. The test structures may also be designed to be actuated after deposition. Observation of their behavior during actuation with the newly deposited films can provide even more information about the residual stress states as well as the change in the film properties over many actuation cycles.
This technique may also be used to determine the stress of films as they are being deposited. With appropriate modification of the deposition system, an optical path may be created allowing the imaging system to view the structures and track the change of their color maps in real time. This would facilitate real-time feedback systems for controlling deposition parameters in an attempt to control residual stress in this manner. The software and hardware may “interrogate” the test wafer on a periodic basis and allow the deposition tool operator to alter conditions as the film grows. Overall this system is superior to other techniques for measuring residual stress, which either rely on electromechanical actuation alone, or utilize expensive and complex interferometric systems to measure the deformation of fabricated structures. The former suffers from a need to provide drive electronics to a large array of devices, and inaccuracies in measuring displacement electronically. The latter is subject to the optical properties of the films under observation, and the complexity of the required external optics and hardware.
Another class of materials with interesting properties are films whose structure is not homogeneous. These films can occur in several forms and we shall refer to them collectively as discontinuous films.
All three of these types of discontinuous films are candidates for inclusion into an IMod structure. That is to say they could act as one or more of the material films in the static and/or movable portions of an IMod structure. All three exhibit unique optical properties which can be manipulated in ways that rely primarily on the structure and geometry of the individual film instead of a combination of films with varying thickness. They can be used in conjunction with other electronic, optical, and mechanical elements of an IMod that they could comprise. In very simple cases, the optical properties of each of these films may be changed by bringing them into direct contact or close proximity to other films via surface conduction or optical interference. This can occur by directly altering the conductivity of the film, and/or by altering the effective refractive index of its surrounding medium. Thus more complex optical responses in an individual IMod may be obtained with simpler structures that have less complex fabrication processes.
Other embodiments are within the scope of the following claims.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US2534846||8 Sep 1947||19 Dec 1950||Emi Ltd||Color filter|
|US3439973||25 Jun 1964||22 Apr 1969||Siemens Ag||Polarizing reflector for electromagnetic wave radiation in the micron wavelength|
|US3443854||25 Jun 1964||13 May 1969||Siemens Ag||Dipole device for electromagnetic wave radiation in micron wavelength ranges|
|US3448334||30 Sep 1966||3 Jun 1969||North American Rockwell||Multicolored e.l. displays using external colored light sources|
|US3653741||16 Feb 1970||4 Apr 1972||Alvin M Marks||Electro-optical dipolar material|
|US3656836||26 Jun 1969||18 Apr 1972||Thomson Csf||Light modulator|
|US3679313||23 Oct 1970||25 Jul 1972||Bell Telephone Labor Inc||Dispersive element for optical pulse compression|
|US3725868||19 Oct 1970||3 Apr 1973||Burroughs Corp||Small reconfigurable processor for a variety of data processing applications|
|US3813265||23 Mar 1972||28 May 1974||Marks A||Electro-optical dipolar material|
|US3955880||15 Jul 1974||11 May 1976||Organisation Europeenne De Recherches Spatiales||Infrared radiation modulator|
|US4099854||12 Oct 1976||11 Jul 1978||The Unites States Of America As Represented By The Secretary Of The Navy||Optical notch filter utilizing electric dipole resonance absorption|
|US4196396||3 May 1978||1 Apr 1980||Bell Telephone Laboratories, Incorporated||Interferometer apparatus using electro-optic material with feedback|
|US4228437||26 Jun 1979||14 Oct 1980||The United States Of America As Represented By The Secretary Of The Navy||Wideband polarization-transforming electromagnetic mirror|
|US4377324||4 Aug 1980||22 Mar 1983||Honeywell Inc.||Graded index Fabry-Perot optical filter device|
|US4389096||23 Feb 1981||21 Jun 1983||Matsushita Electric Industrial Co., Ltd.||Image display apparatus of liquid crystal valve projection type|
|US4403248||4 Mar 1981||6 Sep 1983||U.S. Philips Corporation||Display device with deformable reflective medium|
|US4441791||7 Jun 1982||10 Apr 1984||Texas Instruments Incorporated||Deformable mirror light modulator|
|US4445050||15 Dec 1981||24 Apr 1984||Marks Alvin M||Device for conversion of light power to electric power|
|US4459182||22 Apr 1983||10 Jul 1984||U.S. Philips Corporation||Method of manufacturing a display device|
|US4482213||23 Nov 1982||13 Nov 1984||Texas Instruments Incorporated||Perimeter seal reinforcement holes for plastic LCDs|
|US4500171||2 Jun 1982||19 Feb 1985||Texas Instruments Incorporated||Process for plastic LCD fill hole sealing|
|US4519676||24 Jan 1983||28 May 1985||U.S. Philips Corporation||Passive display device|
|US4531126||17 May 1982||23 Jul 1985||Societe D'etude Du Radant||Method and device for analyzing a very high frequency radiation beam of electromagnetic waves|
|US4566935||31 Jul 1984||28 Jan 1986||Texas Instruments Incorporated||Spatial light modulator and method|
|US4571603||10 Jan 1984||18 Feb 1986||Texas Instruments Incorporated||Deformable mirror electrostatic printer|
|US4596992||31 Aug 1984||24 Jun 1986||Texas Instruments Incorporated||Linear spatial light modulator and printer|
|US4615595||10 Oct 1984||7 Oct 1986||Texas Instruments Incorporated||Frame addressed spatial light modulator|
|US4662746||30 Oct 1985||5 May 1987||Texas Instruments Incorporated||Spatial light modulator and method|
|US4663083||3 Apr 1984||5 May 1987||Marks Alvin M||Electro-optical dipole suspension with reflective-absorptive-transmissive characteristics|
|US4681403||19 Jun 1986||21 Jul 1987||U.S. Philips Corporation||Display device with micromechanical leaf spring switches|
|US4710732||31 Jul 1984||1 Dec 1987||Texas Instruments Incorporated||Spatial light modulator and method|
|US4748366||2 Sep 1986||31 May 1988||Taylor George W||Novel uses of piezoelectric materials for creating optical effects|
|US4786128||2 Dec 1986||22 Nov 1988||Quantum Diagnostics, Ltd.||Device for modulating and reflecting electromagnetic radiation employing electro-optic layer having a variable index of refraction|
|US4790634||4 Sep 1987||13 Dec 1988||The Secretary Of State For Defence In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain And Northern Ireland||Bistable liquid crystal in a fabry-perot etalon|
|US4790635||24 Apr 1987||13 Dec 1988||The Secretary Of State For Defence In Her Brittanic Majesty's Government Of The United Kingdom Of Great Britain And Northern Ireland||Electro-optical device|
|US4856863||22 Jun 1988||15 Aug 1989||Texas Instruments Incorporated||Optical fiber interconnection network including spatial light modulator|
|US4859060||25 Nov 1986||22 Aug 1989||501 Sharp Kabushiki Kaisha||Variable interferometric device and a process for the production of the same|
|US4900395||7 Apr 1989||13 Feb 1990||Fsi International, Inc.||HF gas etching of wafers in an acid processor|
|US4937496||5 May 1988||26 Jun 1990||W. C. Heraeus Gmbh||Xenon short arc discharge lamp|
|US4954789||28 Sep 1989||4 Sep 1990||Texas Instruments Incorporated||Spatial light modulator|
|US4956619||28 Oct 1988||11 Sep 1990||Texas Instruments Incorporated||Spatial light modulator|
|US4982184||3 Jan 1989||1 Jan 1991||General Electric Company||Electrocrystallochromic display and element|
|US5018256||29 Jun 1990||28 May 1991||Texas Instruments Incorporated||Architecture and process for integrating DMD with control circuit substrates|
|US5022745||7 Sep 1989||11 Jun 1991||Massachusetts Institute Of Technology||Electrostatically deformable single crystal dielectrically coated mirror|
|US5028939||26 Jun 1989||2 Jul 1991||Texas Instruments Incorporated||Spatial light modulator system|
|US5037173||22 Nov 1989||6 Aug 1991||Texas Instruments Incorporated||Optical interconnection network|
|US5044736||6 Nov 1990||3 Sep 1991||Motorola, Inc.||Configurable optical filter or display|
|US5061049||13 Sep 1990||29 Oct 1991||Texas Instruments Incorporated||Spatial light modulator and method|
|US5075796||17 Sep 1990||24 Dec 1991||Eastman Kodak Company||Optical article for multicolor imaging|
|US5078479||18 Apr 1991||7 Jan 1992||Centre Suisse D'electronique Et De Microtechnique Sa||Light modulation device with matrix addressing|
|US5079544||27 Feb 1989||7 Jan 1992||Texas Instruments Incorporated||Standard independent digitized video system|
|US5083857||29 Jun 1990||28 Jan 1992||Texas Instruments Incorporated||Multi-level deformable mirror device|
|US5096279||26 Nov 1990||17 Mar 1992||Texas Instruments Incorporated||Spatial light modulator and method|
|US5099353||4 Jan 1991||24 Mar 1992||Texas Instruments Incorporated||Architecture and process for integrating DMD with control circuit substrates|
|US5124834||16 Nov 1989||23 Jun 1992||General Electric Company||Transferrable, self-supporting pellicle for elastomer light valve displays and method for making the same|
|US5136669||15 Mar 1991||4 Aug 1992||Sperry Marine Inc.||Variable ratio fiber optic coupler optical signal processing element|
|US5142405||29 Jun 1990||25 Aug 1992||Texas Instruments Incorporated||Bistable dmd addressing circuit and method|
|US5142414||22 Apr 1991||25 Aug 1992||Koehler Dale R||Electrically actuatable temporal tristimulus-color device|
|US5153771||18 Jul 1990||6 Oct 1992||Northrop Corporation||Coherent light modulation and detector|
|US5162787||30 May 1991||10 Nov 1992||Texas Instruments Incorporated||Apparatus and method for digitized video system utilizing a moving display surface|
|US5168406||31 Jul 1991||1 Dec 1992||Texas Instruments Incorporated||Color deformable mirror device and method for manufacture|
|US5170156||30 May 1991||8 Dec 1992||Texas Instruments Incorporated||Multi-frequency two dimensional display system|
|US5172262||16 Apr 1992||15 Dec 1992||Texas Instruments Incorporated||Spatial light modulator and method|
|US5179274||12 Jul 1991||12 Jan 1993||Texas Instruments Incorporated||Method for controlling operation of optical systems and devices|
|US5192395||12 Oct 1990||9 Mar 1993||Texas Instruments Incorporated||Method of making a digital flexure beam accelerometer|
|US5192946||30 May 1991||9 Mar 1993||Texas Instruments Incorporated||Digitized color video display system|
|US5206629||3 Jul 1991||27 Apr 1993||Texas Instruments Incorporated||Spatial light modulator and memory for digitized video display|
|US5212582||4 Mar 1992||18 May 1993||Texas Instruments Incorporated||Electrostatically controlled beam steering device and method|
|US5214419||26 Jun 1991||25 May 1993||Texas Instruments Incorporated||Planarized true three dimensional display|
|US5214420||26 Jun 1991||25 May 1993||Texas Instruments Incorporated||Spatial light modulator projection system with random polarity light|
|US5216537||2 Jan 1992||1 Jun 1993||Texas Instruments Incorporated||Architecture and process for integrating DMD with control circuit substrates|
|US5226099||26 Apr 1991||6 Jul 1993||Texas Instruments Incorporated||Digital micromirror shutter device|
|US5228013||10 Jan 1992||13 Jul 1993||Bik Russell J||Clock-painting device and method for indicating the time-of-day with a non-traditional, now analog artistic panel of digital electronic visual displays|
|US5231532||5 Feb 1992||27 Jul 1993||Texas Instruments Incorporated||Switchable resonant filter for optical radiation|
|US5233385||18 Dec 1991||3 Aug 1993||Texas Instruments Incorporated||White light enhanced color field sequential projection|
|US5233456||20 Dec 1991||3 Aug 1993||Texas Instruments Incorporated||Resonant mirror and method of manufacture|
|US5233459||6 Mar 1991||3 Aug 1993||Massachusetts Institute Of Technology||Electric display device|
|US5254980||6 Sep 1991||19 Oct 1993||Texas Instruments Incorporated||DMD display system controller|
|US5272473||17 Aug 1992||21 Dec 1993||Texas Instruments Incorporated||Reduced-speckle display system|
|US5278652||23 Mar 1993||11 Jan 1994||Texas Instruments Incorporated||DMD architecture and timing for use in a pulse width modulated display system|
|US5280277||17 Nov 1992||18 Jan 1994||Texas Instruments Incorporated||Field updated deformable mirror device|
|US5287096||18 Sep 1992||15 Feb 1994||Texas Instruments Incorporated||Variable luminosity display system|
|US5287215||17 Jul 1991||15 Feb 1994||Optron Systems, Inc.||Membrane light modulation systems|
|US5293272||24 Aug 1992||8 Mar 1994||Physical Optics Corporation||High finesse holographic fabry-perot etalon and method of fabricating|
|US5296950||31 Jan 1992||22 Mar 1994||Texas Instruments Incorporated||Optical signal free-space conversion board|
|US5305640||1 May 1992||26 Apr 1994||Texas Instruments Incorporated||Digital flexure beam accelerometer|
|US5311360||28 Apr 1992||10 May 1994||The Board Of Trustees Of The Leland Stanford, Junior University||Method and apparatus for modulating a light beam|
|US5312513||3 Apr 1992||17 May 1994||Texas Instruments Incorporated||Methods of forming multiple phase light modulators|
|US5323002||8 Jun 1993||21 Jun 1994||Texas Instruments Incorporated||Spatial light modulator based optical calibration system|
|US5324683||2 Jun 1993||28 Jun 1994||Motorola, Inc.||Method of forming a semiconductor structure having an air region|
|US5325116||18 Sep 1992||28 Jun 1994||Texas Instruments Incorporated||Device for writing to and reading from optical storage media|
|US5326430||7 Dec 1993||5 Jul 1994||International Business Machines Corporation||Cooling microfan arrangements and process|
|US5327286||31 Aug 1992||5 Jul 1994||Texas Instruments Incorporated||Real time optical correlation system|
|US5331454||16 Jan 1992||19 Jul 1994||Texas Instruments Incorporated||Low reset voltage process for DMD|
|US5339116||15 Oct 1993||16 Aug 1994||Texas Instruments Incorporated||DMD architecture and timing for use in a pulse-width modulated display system|
|US5345322||3 May 1993||6 Sep 1994||Manchester R&D Limited Partnership||Complementary color liquid crystal display|
|US5345328||12 Aug 1992||6 Sep 1994||Sandia Corporation||Tandem resonator reflectance modulator|
|US5358601||14 Sep 1993||25 Oct 1994||Micron Technology, Inc.||Process for isotropically etching semiconductor devices|
|US5365283||19 Jul 1993||15 Nov 1994||Texas Instruments Incorporated||Color phase control for projection display using spatial light modulator|
|US20060077124 *||8 Jul 2005||13 Apr 2006||Gally Brian J||Method and device for manipulating color in a display|
|1||"CIE Color System," from website hyperphysics.phy-astr.gsu.edu.hbase/vision/cie.html, (Cited in Notice of Allowance mailed Jan. 11, 2008 in U.S. Appl. No. 11/188,197; The reference includes a date Dec. 30, 2007, however, the Examiner for U.S. Appl. No. 11/188,197 stated that no date was available to cite.).|
|2||"Light Over Matter," Jun. 1993. Circle No. 36.|
|3||"Science and Technology", The Economist, May 22, 1999, pp. 89-90.|
|4||Akasaka, "Three-Dimensional IC Trends," Proceedings of IEEE, vol. 74, No. 12, Dec. 1986, pp. 1703-1714.|
|5||Amendement mailed Jul. 13, 2007 in U.S. Appl. No. 11/432,724.|
|6||Amendment and Response to Office Action mailed Feb. 27, 2007 in U.S. Appl. No. 11/192,436.|
|7||Amendment and Response to Office Action mailed Jun. 27, 2006 in U.S. Appl. No. 11/192,436.|
|8||Amendment and Response to Request for Restriction/Election mailed Aug. 3, 2007 in U.S. Appl. No. 11/433,294.|
|9||Amendment and Response to Request for Restriction/Election mailed Oct. 31, 2006 in U.S. Appl. No. 11/433,294.|
|10||Amendment dated Apr. 21, 2008 in U.S. Appl. No. 11/432,724.|
|11||Amendment dated Mar. 13, 2008 in U.S. Appl. No. 11/742,271.|
|12||Amendment dated Mar. 19, 2008 in U.S. Appl. No. 11/192,436.|
|13||Aratani, et al., "Process and Design Considerations for Surface Micromachined Beams for a Tuneable Interferometer Array in Silicon," IEEE Micro. Workshop, Fort Lauderdale, FL, Feb. 7-10, 1993, pp. 230-235.|
|14||Aratani, et al., "Surface micromachined tuneable interferometer array," Sensors and Actuators A 43, 1994, pp. 17-23.|
|15||Austrian Search Report in U.S. Appl. No. 11/051,258 mailed May 13, 2005.|
|16||Austrian Search Report in U.S. Appl. No. 11/083,841 mailed Jul. 14, 2005.|
|17||Austrian Search Report in U.S. Appl. No. 11/118,110 mailed Aug. 12, 2005.|
|18||Austrian Search Report in U.S. Appl. No. 11/118,605 mailed Jul. 14, 2005.|
|19||Austrian Search Report in U.S. Appl. No. 11/140,561 mailed Jul. 11, 2005.|
|20||Conner, "P-36: Hybrid Color Display Using Optical Interference Filter Array," SID Digest 1993, pp. 577-580.|
|21||Extended European Search Report in European Application No. 06 07 07032 filed Sep. 14, 2005.|
|22||Extended European Search Report in European Application No. EP 05255635 filed Sep. 14, 2005.|
|23||Extended European Search Report in European Application No. EP 05255636 filed Sep. 14, 2005.|
|24||Extended European Search Report in European Application No. EP 05255657 filed Sep. 14, 2005.|
|25||Fan et al., Channel Drop Filters in Photonic Crystals, Optics Express, vol. 3, No. 1, 1998.|
|26||Giles et al., "A Silicon MEMS Optical Switch Attenuator and Its use in Lightwave Subsystems", IEEE Journal of Selected Topics in Quanum Electronics, vol. 5, No. 1, Jan./Feb., 1999, pp. 18-25.|
|27||Goossen, et al., "Possible Display Applications of the Silicon Mechanical Anti-Reflection Switch," Society Information Display, 1994.|
|28||Goossen, et al., "Silicon Modulator Based on Mechanically-Active Anti-Reflection Layer with 1/Mbit/sec Capability for Fiber-in-the-Loop Applications," IEEE Photonics Technology Letters 6, Sep. 1994, No. 9.|
|29||Gosch, "West Germany Graps the Lead in X-Ray Lithography," Electronics, Feb. 5, 1987, pp. 78-80.|
|30||Howard, "Nanometer-Scale Fabrication Techniques," VLSI Electronics: Microstructure Science, vol. 5, 1982, pp. 145-153 and pp. 166-173.|
|31||Ibotson, et al. "Comparison of XeF2, and F-atom reactions with Si and Si02, Applied Physics Letters," vol. 44, No. 12, Jun. 1984, pp. 1129-1131.|
|32||IPER for PCT/US2005/030526 filed Aug. 26, 2005.|
|33||IPER for PCT/US2005/032773 filed on Sep. 14, 2005.|
|34||ISR and WO for PCT/US2005/030526 filed Aug. 26, 2005.|
|35||ISR and WO for PCT/US2005/032773 filed on Sep. 14, 2005.|
|36||ISR and WO in International Application No. PCT/US07/08790 dated Nov. 2, 2007.|
|37||ISR and WO in International Application No. PCT/US2005/032426 dated Jan. 11, 2006.|
|38||ISR and WO in US/2005/032335 filed on Sep. 9, 2005.|
|39||Jackson, "Classical Electrodynamics," John Wiley & Sons Inc., 1962, pp. 568-573.|
|40||Jackson, "Classical Electrodynamics," John Wiley & Sons Inc., pp. 568-573.|
|41||Jerman et al., "A Miniature Fabry-Perot Interferometer with a Corruggated Silicon Diaphragm Support," Sensors and Actuators A, vol. 29, pp. 151, 1991.|
|42||Joannopoulos et al., Photonic Crystals, "Molding the Flow of Light", Copyright 1995.|
|43||Johnson, "Optical Scanners," Microwave Scanning Antennas, vol. 1, 1964, pp. 251-261.|
|44||Kim et al., "Contro of Optical Transmission Through metals Perforated With Subwavelength Hole Arrays", Optic Letters, vol. 24, No. 4, Feb. 15, 1999, pp. 256-257.|
|45||Lin et al., "Free-Space Micromachined Optical Switches for Optical Networking", IEEE Journal of Selected Topics in Quantum Electronics, vol. 5, No. 1, Jan./Feb. 1999, pp. 4-9.|
|46||Little et al., "Vertically Coupled Microring Resonator Channel Dropping Filter", IEEE Photonics Technology Letters, vol. 11, No. 2, 1999.|
|47||Magel, "integrated Optic Devices Using Micromachined Metal Membranes", SPIE vol. 2686, 0-8194-2060-3/1996.|
|48||Manzardo, et. al., "Optics and Actuators for miniaturized spectometers", International Conference on Optical MEMS, vol. 12, Issue 6, Dec. 2003, pp. 23-24.|
|49||Miles, M., et.al., "Digital Paper for Reflective Displays", Hournal of SID, vol. 11, No. 1, 2003, pp. 209-215.|
|50||Miles, M.W., "Interferometric modulation: MOEMS as an enabling technology for high-performance reflective displays," Proceedings of the SPIE, SPIE, Bellingham, VA, US, vol. 4895, Jan. 28, 2003, pp. 131-139.|
|51||Miles, Mark W., "A New Reflective FPD Technology Using Interferometric Modulation," Society for Information Display, 1997 Digest, Session 7.3.|
|52||Miles, MW "A MEMS Based Interferometric Modulator (IMOD) for Display Applications" Proceedings of Sensors Expo, Oct. 21, 1997 (C) 1997 Helmer's Publishing, Inc. (Oct. 21, 1997), pp. 281-284.|
|53||Nagami et al., "Plastic Cell Architecture: Towards Reconfigurable Computing for General-Purpose", IEEE, 0-8186-8900-May 1998, pp. 68-77.|
|54||Newsbreaks. "Quantum-trench Devices Might Operate at Terahertz Frequencies," Laser Focus World, May 1993.|
|55||Notice of Allowance mailed Jul. 5, 2007 in U.S. Appl. No. 11/192,436.|
|56||Office Action mailed Apr. 13, 2007 in U.S. Appl. No. 11/432,724.|
|57||Office Action mailed Dec. 13, 2007 in U.S. Appl. No. 11/742,271.|
|58||Office Action mailed Dec. 21, 2007 in U.S. Appl. No. 11/432,724.|
|59||Office Action mailed Feb. 27, 2007 in U.S. Appl. No. 11/192,436.|
|60||Office Action mailed Jun. 27, 2006 in U.S. Appl. No. 11/192,436.|
|61||Office Action mailed Mar. 17, 2008 in U.S. Appl. No. 11/433,294.|
|62||Office Action mailed on Nov. 19, 2007 in U.S. Appl. No. 11/192,436.|
|63||Office Action mailed Sep. 11, 2007 in U.S. Appl. No. 11/432,724.|
|64||Oliner, "Radiating Elements and Mutual Coupling," Microwave Scanning Antennas, vol. 11, 1966, pp. 131-157 and pp. 190-194.|
|65||Oliner, "Radiating Elements and Mutual Coupling," Microwave Scanning Antennas, vol. 2, p. 131 et seq.|
|66||Partial European Search Report in European Application No. 06 07 7032 filed Sep. 14, 2005.|
|67||Raley et al., "A Fabry-Perot Microinterferometer for Visible Wavelengths," IEEE Solid-State Sensor and Actuator Workshop, Jun. 1992, Hilton Head, SC.|
|68||Request for Continued Examination and Amendment mailed Oct. 31, 2007 in U.S. Appl. No. 11/432,724.|
|69||Request for Continued Examination mailed Apr. 27, 2007 in U.S. Appl. No. 11/192,436.|
|70||Request for Continued Examination mailed Oct. 4, 2007 in U.S. Appl. No. 11/192,436.|
|71||Request for Restriction/Election mailed Apr. 20, 2007 in U.S. Appl. No. 11/433,294.|
|72||Request for Restriction/Election mailed Aug. 3, 2007 in U.S. Appl. No. 11/433,294.|
|73||Request for Restriction/Election mailed Jan. 4, 2007 in U.S. Appl. No. 11/432,724.|
|74||Request for Restriction/Election mailed Oct. 31, 2006 in U.S. Appl. No. 11/433,294.|
|75||Requirement for Restriction/Election mailed Mar. 17, 2006 in U.S. Appl. No. 11/192,436.|
|76||Response to Request for Restriction/Election mailed Apr. 20, 2007 in U.S. Appl. No. 11/433,294.|
|77||Response to Request for Restriction/Election mailed Jan. 17, 2007 in U.S. Appl. No. 11/432,724.|
|78||Response to Requirement for Restriction/Election mailed Mar. 17, 2006 in U.S. Appl. No. 11/192,436.|
|79||Schnakenberg, et al. "THAHW Etchants for Silicon Micromachining." 1991 International Conference on Solid State Sensors and Actuators-Digest of Technical Papers. pp. 815-818.|
|80||Sperger et al., "High Performance Patterned All-Dielectric Interference Colour Filter for Display Applications," SID Digest 1994, pp. 81-83.|
|81||Stone, "Radiation and Optics, An Introduction to the Classical Theory," McGraw-Hill, 1963, pp. 340-343.|
|82||Stone, "Radiation and Optics, An Introduction to the Classical Theory," McGraw-Hill, pp. 340-343.|
|83||Walker et al., "Electron-beam-tuneable Interference Filter Special Light Modulator," Optics Letter vol. 13, No. 5, pp. 345-347, 1988.|
|84||Williams, et al. Etch Rates for Michromachining Processing-Journal of Microelectromechanical Systems vol. 5 No. 4, Dec. 1996, pp. 256-269.|
|85||Winters, et al., "The Etching of Silicon with XeF2 Vapor. " Applied Physics Letters, vol. 34, No. 1, Jan. 1979, pp. 70-73.|
|86||Winton, John M., "A novel way to capture solar energy," Chemical Week, May 15, 1985, pp. 17-18.|
|87||Wu, "Design of a Reflective Color LCD Using Optical Interference Reflectors, " ASIA Display 1995, Oct. 16, 1995, pp. 929-931.|
|88||Zhou et al., "Waveguide Panel Display Using Electromechanisl Spatial Modulators" SID Digest, vol. XXIX, 1998.|
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|US20060066641 *||19 Aug 2005||30 Mar 2006||Gally Brian J||Method and device for manipulating color in a display|
|US20060077124 *||8 Jul 2005||13 Apr 2006||Gally Brian J||Method and device for manipulating color in a display|
|US20060077148 *||29 Apr 2005||13 Apr 2006||Gally Brian J||Method and device for manipulating color in a display|
|US20060077149 *||29 Apr 2005||13 Apr 2006||Gally Brian J||Method and device for manipulating color in a display|
|US20060077512 *||4 Feb 2005||13 Apr 2006||Cummings William J||Display device having an array of spatial light modulators with integrated color filters|
|US20070132843 *||24 Jan 2007||14 Jun 2007||Idc, Llc||Method and system for interferometric modulation in projection or peripheral devices|
|US20070247704 *||21 Apr 2006||25 Oct 2007||Marc Mignard||Method and apparatus for providing brightness control in an interferometric modulator (IMOD) display|
|US20070253054 *||30 Apr 2007||1 Nov 2007||Miles Mark W||Display devices comprising of interferometric modulator and sensor|
|WO2010111186A1||22 Mar 2010||30 Sep 2010||Qualcomm Mems Technologies, Inc.||Dithered holographic frontlight|
|U.S. Classification||359/290, 359/302|
|International Classification||G09G3/34, G02B26/02, B81B3/00, G02B6/43, G02B6/35, G01J3/26, G02B6/26, G02B26/00, G01L5/00, G02B6/122, G02B6/12, G02B26/08, G02B6/13|
|Cooperative Classification||G02B5/02, G02B26/02, G02B6/3516, G02B6/3584, G02B6/13, G02B6/266, G02B6/3548, G02B6/12007, G09G2310/02, G02B6/3546, G02B6/3536, G09G2310/0254, G09G3/3466, G02B2006/12109, G09G2310/06, G02B2006/12126, G02B6/122, G02B2006/12159, G02B26/08, G02B6/357, G02B6/3522, G02B6/356, G02B26/0841, G01J3/0256, B82Y20/00, G02B26/0833, G02B2006/12164, G02B6/3594, G02B6/3598, G02B2006/12104, G02B6/3578, G02B6/43, G02B6/353, G02B26/001, G02B6/1225, G01J3/26, G01L5/0047|
|European Classification||B82Y20/00, G02B6/35E4, G02B5/02, G02B26/08, G02B6/35E2L, G02B26/02, G02B26/08M4E, G01J3/26, G02B6/12M, G09G3/34E8, G02B6/13, G02B6/122P, G02B6/43, G02B6/35G, G02B26/00C, G01L5/00G, G02B6/122, G02B26/08M4|
|30 Oct 2009||AS||Assignment|
Owner name: QUALCOMM MEMS TECHNOLOGIES, INC., CALIFORNIA
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:IDC,LLC;REEL/FRAME:023449/0614
Effective date: 20090925
|10 Nov 2009||CC||Certificate of correction|
|25 Jun 2012||FPAY||Fee payment|
Year of fee payment: 4